RU2707236C2 - Method (embodiments) for elimination of consequences of leak of vehicle injector - Google Patents

Abstract

FIELD: internal combustion engines.

SUBSTANCE: invention can be used in internal combustion engine fuel feed control systems. Disclosed are methods and systems for eliminating consequences of leaks of fuel injector in conditions of engine idling. In accordance with one of the examples of implementation, the method under the invention may include during or after engine stop, identification of engine cylinder with fuel injector leakage and engine installation, for example, by its electric motor rotation, into position selected depending on identified cylinder, so that the identified valve outlet valve is at least partially open.

EFFECT: invention allows increasing stability of start-up and operation of the engine after its stop in case of leakage of injector, as well as reducing toxicity of exhaust gases due to discharge of vapours of leaked fuel from the cylinder into the catalytic neutraliser.

18 cl, 6 dwg

Description

FIELD OF THE INVENTION

The present invention generally relates to methods and systems for controlling a vehicle engine with a fuel injector leaking during engine idle stops.

State of the art

Engine fuel injectors can degrade, resulting in fuel leaks in the respective engine cylinders. The presence of such leaks of fuel injectors can lead to increased fuel consumption, increased emissions and the occurrence of failures when starting the engine. Known attempts to eliminate the disadvantages associated with the leakage of fuel injectors may include the adoption of corrective measures performed during engine operation. In accordance with one example of a known solution for compensating for fuel loss caused by a leak, a lean air-fuel mixture is supplied to a cylinder with a fuel injector leak and / or other cylinders with a lean air-fuel ratio are operated.

However, the inventors of the present invention have found that the aforementioned solution has the disadvantage that the above corrective measures can only be applied while the engine is running, and not when the engine is off. In particular, the application of corrective measures taken with the engine running can be difficult in vehicles configured to automatically shut off the engine. For example, moving a vehicle in a dense traffic stream may require frequent stopping and starting the engine. Fuel leaks from the injector during such engine shutdown periods can cause malfunctions during subsequent engine start-ups, in particular misfire, vehicle jerking, air bubbles entering the fuel system, etc., as well as an increase in vehicle emissions. Fuel leaks during long downtimes with engine shutdown can also lead to fuel leaking through the piston rings into the crankcase, in which it can dilute the engine oil and reduce engine lubrication, which increases the likelihood of engine damage.

Disclosure of invention

To at least partially eliminate the consequences of leaks of fuel injectors of vehicles, for example, made with the possibility of a long stop of the engine idling, a method of engine operation is proposed, which includes identifying the engine cylinder with a fuel injector leak and during or after engine shutdown, engine installation to a position selected depending on the identified cylinder, so that the outlet valve of the identified cylinder is at least partially open. The installation of the identified cylinder in the open exhaust valve position while the engine is idling stops the fuel leaking from the injector from the heated cylinder walls and evaporates as a result of natural diffusion through the open exhaust valve into the downstream catalytic converter, in which the leaking vapor fuels can be processed with subsequent release to the atmosphere. According to one embodiment, the starter motor can be used to shift the engine to a position determined depending on the identified cylinder with the current injector, so that the exhaust valve of the identified cylinder would be at least partially open during engine idle stops .

The solution of the present invention has several advantages. In particular, the method according to the invention can provide reduced emissions, misfires, uneven engine operation and engine damage in vehicles used for driving in urban areas with long engine idle stops.

It should be understood that the above brief description is only for acquaintance in a simple form with some concepts, which will be further described in detail. This description is not intended to indicate key or essential distinguishing features of the claimed subject matter, the scope of which is uniquely defined by the claims given after the section "Implementation of the invention". In addition, the claimed subject matter is not limited to implementations that eliminate any of the disadvantages indicated above or in any other part of this disclosure.

Brief Description of the Drawings

In FIG. 1 is a diagram of a fuel system connected to a propulsion system.

In FIG. 2 shows a diagram of an internal combustion engine.

In FIG. 3 is a flowchart illustrating an example implementation of a procedure for detecting an engine cylinder with a fuel injector leaking and changing the position of the engine while the engine is idling.

In FIG. 4 is a flowchart illustrating an example of a procedure for changing the position of the engine to a position determined depending on the identified cylinder in accordance with the method of FIG. 3.

In FIG. Figure 5 shows examples of graphs of pressure in the fuel rail and the operation of the fuel pump when the engine is idling.

In FIG. Figure 6 shows examples of graphs of engine parameters during engine shutdown in the presence of a fuel injector leak.

The implementation of the invention

The following description discloses systems and methods for controlling a vehicle engine with a fuel injector leak during engine shutdowns. According to one embodiment, the vehicle system comprises an engine for which fuel can be provided by a fuel system, for example, having the configuration of FIG. 1. A detailed diagram of one of the engine cylinders is shown in FIG. 2. FIG. 3 and 4 illustrate methods for identifying an engine cylinder with a fuel injector leak and changing the position of the engine during stops with the engine turned off to eliminate the effects of a fuel leak. In FIG. 5 shows examples of fuel pump operation graphs and fuel rail pressure with the engine turned off, and FIG. Figure 6 shows examples of graphs of the position of the intake and exhaust valves after changing the position of the engine cylinder in a four-stroke cycle of the engine using the starter motor.

In FIG. 1 illustrates a vehicle system 1 comprising a fuel system 20. Fuel system 20 provides fuel to an engine 10 comprising a plurality of cylinders 30. Fuel system 20 comprises a fuel tank 11 for storing fuel on board a vehicle, and a fuel pump 4 for injecting fuel under high pressure fuel rail 2 high pressure. The high pressure fuel rail 2 comprises a fuel rail pressure sensor 3 for monitoring fuel pressure in the fuel rail.

Fuel rail 2 delivers high pressure fuel to cylinders 30 through a plurality of direct injection fuel injectors 66. According to the present embodiment, the fuel system 20 comprises only direct injection injectors 66. However, this embodiment corresponds to only one example of a fuel system configuration, which in other embodiments may comprise additional components (or contain fewer components) without departing from the spirit of the present invention. For example, fuel system 20 may additionally or alternatively comprise distributed injection fuel injectors.

The high pressure fuel pump 4 compresses the fuel for supply through the fuel rail 2. The fuel passes through the fuel rail 2 to at least one fuel injector 66 and enters at least one cylinder 30 of the engine, in which the fuel is burned to supply energy to the vehicle. To reduce the likelihood of engine degradation, a common rail fuel system is monitored for fuel leaks. According to one embodiment, the fuel rail pressure sensor 3 monitors the fuel pressure in the fuel rail. It may also be possible to monitor the operability of individual direct injection fuel injectors 66, for example, by measuring the fuel pressure in the fuel rail before and after the injection produced by each of the engine fuel injectors, and the degradation of a particular fuel injector is detected if the pressure drop in the fuel rail exceeds the pressure after injection produced by this injector is the expected value.

The engine 10 is connected to the exhaust channel 5 of the engine through the exhaust manifold 48, directing the exhaust gases into the atmosphere. The exhaust channel 5 contains one or more means 70 of reducing the toxicity of emissions, installed end-to-end with each other. The means 70 for reducing emissions may include a three-way catalytic converter (TCH), a depleted nitrogen oxide (NOx) trap, an oxidizing catalyst, etc. Oxygen sensors 6 and 7 are provided at the inlet and outlet of the emission control means 70. As shown in the diagram, a universal exhaust gas oxygen sensor (UCOG) 126 is connected to the exhaust manifold 48 upstream of the emission control means 70. In an alternative embodiment, a dual-position exhaust gas oxygen sensor may be used in place of the UDCOG type sensor 126. Each of the oxygen sensors 6 and 7 may also be a broadband sensor, a narrowband sensor, a heated sensor, or another suitable sensor.

The vehicle system 1 further comprises a front-mounted attachment drive 9 (PNOP) connecting the engine 10 to one or more loads. Such loads may include, for example, but not exclusively, a generator, an air conditioning compressor, a water pump and other related equipment.

In FIG. 2 shows one of the cylinders of the engine 10 of FIG. 1. An internal combustion engine 10 comprising a plurality of cylinders, one of which is shown in FIG. 2, is controlled by a controller 12. The engine 10 comprises combustion chambers 30 with cylinder walls 32 and a piston 36 located between them and connected to the crankshaft 40. As shown in the diagram, the combustion cylinder 30 communicates with the intake manifold 44 and the exhaust manifold 48 through respective inlet valve 52 and exhaust valve 54. An intake cam 51 and an exhaust cam 53 may be provided for actuating the intake and exhaust valves. In an alternative embodiment, for actuating one or several of the inlet and outlet valves, kits of an armature and inductance coil with electromechanical control may be provided. The position of the intake cam 51 can be detected by the intake cam sensor 55. The position of the exhaust cam 53 can be detected by the exhaust cam sensor 57.

As shown in the diagram, the fuel injector 66 is arranged to inject fuel directly into the cylinder 30 in accordance with a configuration known to those skilled in the art as a direct injection system. In an alternative embodiment, the fuel can be injected into the inlet port in accordance with a configuration known to those skilled in the art as a distributed injection system. The fuel injector 66 introduces a fuel amount proportional to the pulse width of the IWT signal coming from the controller 12. The fuel enters the fuel injector 66 from the fuel system 20 of FIG. 1. Fuel injector 66 receives operating current from a driver controlled by controller 12. In addition, as shown in the diagram, intake manifold 44 communicates with an optional electronic air throttle valve 62, which changes the position of the throttle plate 64 to control the air supply from the air intake 42 into the intake manifold 44. According to one embodiment, a two-stage high pressure fuel system can be used to provide a higher fuel pressure. The ignition coil 88 enables the spark plug 92 to form an ignition spark inside the combustion chamber 30 in accordance with the signals from the controller 12.

The engine starter 96 may selectively drive a flywheel 98 connected to the crankshaft 40 to rotate the crankshaft 40. The engine starter 96 may be driven in accordance with a signal from the controller 12. In accordance with some embodiments, engine starter 96 can be activated without the driver entering a special engine stop / start command (for example, using the ignition key or button). Instead, the engine starter 96 can be driven by a gear when the driver releases the brake pedal or depresses the accelerator pedal 130 (for example, using input means that are not limited to stopping and / or starting the engine). In this way, it is possible to automatically start the engine using the engine starter 96 to save fuel.

Controller 12 is shown in FIG. 2 in the form of a microcomputer comprising: a microprocessor device 102 (MPU), input / output ports 104, read-only memory 106 (ROM), random access memory 108 (RAM), non-volatile memory 110 (EZU) and a data bus. The controller 12 may receive, in addition to the signals discussed above, a variety of signals from sensors associated with the engine 10, among which are: an indication of the temperature of the engine coolant (TCD) from the temperature sensor 112 associated with the cooling jacket 114; the reading of the position sensor 134 associated with the accelerator pedal 130 for measuring the force exerted by the foot 132; the air pressure signal in the manifold (DVK) from the sensor 122 associated with the intake manifold 44; the reading of the engine position sensor from the sensor 118 on the Hall effect, measuring the position of the crankshaft 40; indication of the mass flow rate of air entering the engine from the sensor 120; barometric pressure reading from sensor 124; and an indication of the position of the throttle valve of the air intake from the sensor 58. In accordance with a preferred aspect of the present invention, the engine position sensor 118 outputs a predetermined number of uniformly distributed pulses at each revolution of the crankshaft, from which the engine speed (CVR) can be determined. In addition, the controller 12 adjusts the strength of the current supplied to the field winding 97 to control the amount of torque supplied by the starter 96 to the crankshaft 40.

In accordance with some of the embodiments, an internal combustion engine may be coupled to an electric motor / battery system within a hybrid vehicle. The hybrid vehicle may be configured in accordance with a parallel configuration, a serial configuration, or combinations thereof. In addition, in accordance with some of the embodiments, other types of engines, such as a diesel engine, can be used.

Controller 12 receives signals from various sensors of FIG. 1 and 2 and drives the various actuators of FIG. 1 and 2 to regulate the operation of the engine depending on the received signals and instructions stored in the controller memory. For example, adjusting the position of the engine (for example, changing the position of the engine or components of one of the cylinders) may include turning on the starter motor 96 of FIG. 2 and its effect on the cranked flywheel 98 to adjust the position of the engine. In accordance with another example, the adjustment of the engine position can be made by additionally adjusting the engine load created by one or more of the load elements connected to the PNOP 9, adjusting the generator excitation current, or using other appropriate mechanisms to adjust the engine load.

According to one embodiment, adjusting the position of the engine may include rotating the crankshaft of the engine mechanically coupled through a cam chain / timing belt to the exhaust camshaft to adjust the angular position of the camshaft and therefore the position of the exhaust valves driven by this camshaft shaft. Since this adjustment of the camshafts to change the position of the exhaust valves can also change the position of the pistons inside the cylinder, the desired final position after the adjustment can be chosen so that at least one exhaust valve of the selected cylinder with the current fuel injector is at least partially open due to surface pressure cam of the exhaust camshaft onto the exhaust valve stem directed against the action of its return spring, as a result of which second valve maintains its open position after stopping the engine. Thus, when the rotation of the engine is stopped and its rotation frequency is zero, it is possible to evaporate the fuel flowing into the cylinder under the influence of the residual heat of the exhaust released by the cylinder walls and / or the piston surface, and its output due to the natural gas flow through at least partially open the exhaust valve to a downstream catalyst for processing therein.

It should be noted that in accordance with some of the embodiments, if the controller detects several current injectors, the system can determine the most leaky injector. In this case, as the desired cylinder, the exhaust valve of which must be opened while the engine is in a stopped state after engine operation and remain in this position from the moment of stop until the engine temperature drops to a value lower than the threshold, for example, corresponding to the temperature for stopping the evaporation of fuel, a cylinder containing the largest flow injector may be selected. According to another embodiment, if the engine is stopped while the engine is running, and the engine has not yet been warmed to a temperature exceeding such a threshold temperature, the engine can be stopped without further adjustment to ensure that the exhaust valve of the selected cylinder opens. Under such low temperature conditions, the selected cylinder may, for example, be in a state in which its exhaust valve is completely closed.

In the operating mode, each of the cylinders of the engine 10, as a rule, goes through a four-stroke cycle: this cycle includes an intake stroke, a compression stroke, an expansion stroke and a release stroke. At the intake stroke, the exhaust valve 54 is usually closed and the intake valve 52 is opened. Air enters the combustion chamber 30 through the intake manifold 44, and the piston 36 moves to the bottom of the cylinder to increase the internal volume of the combustion chamber 30. Specialists in this field usually refer to the position in which the piston 36 is located near the bottom of the cylinder at the end of its stroke (for example, corresponding to the largest volume of the combustion chamber 30) as the bottom dead center (BDC). At the compression stroke, the inlet valve 52 and the exhaust valve 54 are closed. The piston 36 moves towards the cylinder head to compress the air inside the combustion chamber 30. Piston 36 moves toward the cylinder head so as to compress the air within the combustion chamber 30. Those skilled in the art generally refer to the position where the piston 36 is located at the end of its stroke near the cylinder head (for example, corresponding to the smallest volume of the combustion chamber 30) as top dead point (TDC). In the operation referred to as injection in the present description, fuel is introduced into the combustion chamber. In the operation referred to as ignition in the present description, ignition of the injected fuel is carried out using known ignition means, for example, spark plug 92, which leads to combustion of the fuel. On the expansion stroke, the expanding gases again move the piston 36 to the BDC. The crankshaft 40 converts the translational motion of the piston into the rotational motion of the rotating shaft. Finally, at the exhaust stroke, the exhaust valve 54 opens to release the burnt air-fuel mixture to the exhaust manifold 48 and the piston returns to the TDC. It should be noted that the above description is provided solely as an example, and the opening and / or closing time of the intake and exhaust valves may be different, for example, using positive or negative valve shutoff, delayed closing of the intake valve or other changes.

As indicated above, fuel injectors, for example, the above-described fuel injector 66, may be subject to degradation in which fuel leaks into the corresponding cylinder (e.g., cylinder 30). During engine operation, the effects of a fuel injector leak can be compensated by reducing the amount of fuel injected by this injector in accordance with the control signal, and / or reducing the amount of fuel injected into one or more of the engine cylinders to maintain the torque required by the operator and the stoichiometric total air -fuel relations. However, such countervailing measures do not eliminate the consequences of fuel leaks that may occur after engine shutdown. Leakage of fuel into the cylinder when the engine is stopped can lead to malfunctions during the subsequent engine start, in particular, misfire, jerking in the movement of the vehicle and air bubbles entering the fuel system. Such malfunctions can be amplified in a vehicle with the function of stopping and starting the engine at idle (“stop-start”), since in such vehicles more stops and subsequent engine starts are made. In addition, in a fuel ramp designed to supply fuel to a fuel injector with a high-pressure leak, the fuel pressure during shutdowns with the engine turned off may be higher than during normal engine shutdown at the request of the operator, for example, to accelerate engine restart by the end of the stop. In this regard, it is possible fuel leakage from this injector during engine idle stop.

In accordance with the presented embodiments of the present invention, it is possible to detect a leak of a fuel injector of an engine and to identify a cylinder having a leak of a fuel injector. After identifying the cylinder with the current injector, the engine can be installed when the engine is stopped in the selected position, so that the exhaust valve of the identified cylinder with the current injector is at least partially open (for example, at the exhaust stroke of the identified cylinder). An electric motor, for example, a starter motor 96 of FIG. 2, to rotate the engine to the selected position. This makes it possible to move the fuel flowing out of the current injector after the engine is stopped through the open exhaust valve to a downstream catalytic converter in which the fuel vapor can be converted, thereby reducing vehicle emissions and preventing malfunctions during subsequent engine restart and damage engine.

In FIG. 3 is a flowchart of an embodiment of a method 300 for identifying an injector leak and moving an engine with a current fuel injector when the engine is idling. Instructions for executing the method 300 and other methods of the present invention may be executed by the controller in accordance with the instructions stored in the controller memory and in combination with signals received from sensors of the propulsion system, for example, described above with reference to FIG. 1 and 2. The controller may use actuators of the propulsion system to adjust engine operation in accordance with the methods described below.

At 302, method 300 determines engine operating parameters, which may include engine load, engine temperature, engine speed, etc. After determining the engine operating conditions and if the conditions for diagnosing the fuel injectors are met, the method proceeds to step 304, where the diagnostic procedure for the fuel injectors can be performed. For example, a fuel injector diagnostic procedure may be started if, at step 302, engine parameters are detected that correspond to a high engine load. According to another embodiment, the fuel injector diagnostic procedure may be started after the vehicle has traveled a predetermined distance. In accordance with one example of diagnosing a fuel leak when the engine is running without load, the fuel pump can be stopped, and pressure in the fuel rail can be measured before and after fuel injection using a pressure gauge in the fuel rail, for example, pressure sensor 3 in the fuel rail of FIG. 1, and the obtained differential pressure value can be used to detect leaks in the fuel injection system. After diagnosing a fuel leak, method 300 proceeds to step 306 to detect a current fuel injector in the engine. If there is no detection of an injector leak at step 306, the engine continues to run, and the method proceeds to step 318, where the conditions for stopping the engine at idle are evaluated. To evaluate the conditions for stopping the engine at idle, for example, sensors measuring the engine speed, the position of the brake pedal and the position of the accelerator pedal can be used. For example, conditions for stopping the engine at idle may correspond to a state in which the brake pedal is depressed by the vehicle operator, the engine speed is below the threshold value and / or the torque required by the operator is below the threshold value. If the conditions for stopping the engine idling are met, method 300 proceeds to step 322, where the engine operation parameters are saved, and then method 300 terminates. If the conditions for stopping the engine idling at step 318 are not met, method 300 proceeds to step 320, where the engine is turned off without changing the state of the cylinders. In accordance with one embodiment, turning off the engine without changing the state of the cylinders includes stopping fuel injection, turning off the ignition, and spontaneously slowing down the rotation of the engine until it stops in an arbitrary position. Then, method 300 terminates.

If an injector leak is detected in step 306, method 300 proceeds to step 307 to determine if current fuel injectors are present in one or more cylinders. In accordance with one embodiment, a pressure-based diagnostic procedure may be performed, in which the fuel rail pressure sensor measures the pressure in the fuel rail before and after fuel injection with each of the plurality of fuel injectors, and a faulty fuel injector is identified pressure drop. However, other mechanisms for determining current fuel injectors may be provided within the scope of the present invention. If, at step 307, several current injectors are detected, method 300 proceeds to step 309 to identify the cylinder with the largest leak. The method then proceeds to step 310. If at step 307 one current injector is detected, method 300 proceeds to step 308 to identify the current injector, and then proceeds to step 310.

After identifying the current injector, method 300 proceeds to step 310 to resume normal (i.e., without diagnostics) engine operation, if necessary. Then, the method 300 proceeds to step 312 to adjust the air-fuel ratio (WTO) in one or more cylinders to eliminate the effects of leakage of the fuel injectors. According to one embodiment, the amount of fuel supplied to one or more of the remaining cylinders (e.g., cylinders not containing current fuel injectors) in a subsequent engine cycle can be changed to compensate for the leakage of the corresponding amount of fuel into the identified cylinder. Additionally or alternatively, the amount of fuel supplied to the cylinder (s) with the current injectors can be changed (for example, reduced) to compensate for the amount of fuel leaking into these cylinders. At step 314, checks are made to verify that the conditions for a subsequent engine shutdown are idling. If the conditions for stopping the engine idling are not met, method 300 proceeds to step 312 again.

If the conditions for stopping the engine idle are satisfied, method 300 proceeds to step 315 to determine the engine temperature, and if it is below a threshold value, method 300 proceeds to step 317, where the engine is turned off without setting the identified cylinder to a specific position. Under such low temperature conditions, the identified cylinder may be left, for example, in a state in which its exhaust valve is completely closed. In accordance with one example implementation at a temperature lower than the threshold value at which evaporation of the fuel no longer occurs, the engine is stopped without changing position

identified cylinder. According to another embodiment, if the engine is idling while the engine is running, when the engine has not yet been warmed to a temperature exceeding the threshold value, the engine can be stopped without further adjustment to put the selected cylinder in the position where its exhaust valve is open.

As indicated above, the threshold temperature can be set based on the temperature of evaporation of the fuel. If the engine temperature is below the threshold, the fuel flowing out of the injector may remain in the form of liquid, for example, on the walls of the cylinder and cannot exit through an open exhaust valve. Accordingly, the refusal to change the position of the engine under these conditions provides the opportunity to save energy needed to rotate the engine. In addition, the threshold temperature can be set taking into account the volatility of the fuel. For example, the threshold temperature may be lower for fuels with a higher ethanol content (e.g., E100 fuels) than for fuels with a lower ethanol content (e.g., gasoline). Then, method 300 terminates.

If the engine temperature measured in step 315 exceeds the threshold, the method proceeds to step 316 to stop the engine and change the position of the engine so as to provide a certain state of the cylinder with the current fuel injector, for example, corresponding to the exhaust stroke, so that the exhaust valve is at least at least partially open, which facilitates the removal of leaking fuel vapors from the cylinder, as described in more detail below with reference to FIG. 4.

In FIG. 4 shows an example implementation of a method 400 for eliminating the effects of a fuel leak from a current fuel injector identified in an engine cylinder. Method 400 can be performed if a leak is detected in the fuel injector of the engine cylinder when there is a request to stop the engine. According to one exemplary embodiment, method 400 can be performed as part of the above method 300. At step 402, an engine is stopped in the event of a request to stop the engine at idle. For example, they stop injecting fuel, turn off the ignition, etc., which leads to a spontaneous deceleration of the rotation of the engine until it stops. At the time the engine is stopped, or after it has stopped completely, method 400 proceeds to step 404. At step 404, the end position of the engine is determined. For example, the angular position of the crankshaft can be measured using a sensor, for example, the engine position sensor 118 of FIG. 2 to determine the position of the piston and the corresponding stroke at which the identified cylinder is supposed to be after the engine has stopped.

Then, the method 400 proceeds to step 406, in which it is determined whether the engine is or will be in a predetermined position after stopping, and the identified cylinder must be in a predetermined position after the engine stops at the exhaust stroke or in a different state in which its exhaust valve at least partially open. If this is not the case, the process proceeds to step 418, in which the engine is repositioned and moved to such a position, so that the exhaust valve of the identified cylinder with the current m, the fuel injector is open. According to one embodiment, a change in engine position may include the rotation of the engine by an electric motor, such as a starter motor, at 420. For example, the starter motor may rotate the engine until the identified cylinder is in its exhaust stroke state. In accordance with other exemplary embodiments, an additional load may be used at 422 to influence the rotation of the engine so as to ensure that it stops at a position corresponding to the exhaust stroke of the identified cylinder. In accordance with one embodiment, the rotation of the engine by the electric motor to achieve a predetermined position of the engine includes determining a first angle of rotation in a forward direction necessary to achieve a desired position, and determining a second angle of rotation in a reverse direction necessary to achieve a desired position. The direction of rotation can be selected in accordance with the smallest angle of rotation necessary to achieve the desired position, that is, if the first angle of rotation is greater than the second angle of rotation, the engine is rotated in the opposite direction by a second angle of rotation, and if the first angle of rotation is smaller than the second angle of rotation, the engine rotate forward to the first angle of rotation. According to another embodiment, a change in engine position may include a step 424 for rotating the crankshaft mechanically connected by a cam timing belt to the camshaft, as a result of which it drives the camshaft and sets the cam so that its surface pressure exerts on the exhaust valve stem directed against the action of the return spring, ensured the preservation of its open position after stopping the engine. Then, method 400 proceeds to step 408.

If it is determined at step 406 that the cylinder is on the exhaust stroke, no engine position changes are made, and the method 400 proceeds to step 408. At 408, leaked fuel vapors exit the cylinder with the current fuel injector set to the exhaust stroke position through an open or a partially open exhaust valve as a means of reducing emissions, which may be a three-way catalytic converter. At step 410, a subsequent request to start the engine is reviewed. According to one embodiment, a controller, for example, a controller 12 shown in FIG. 2, may signal that there is a request to restart the engine at idle if the vehicle operator releases the brake pedal. In the absence of a request to start the engine, the engine remains in a idle stop state with the containment / conversion of leaking fuel vapor in the catalytic converter. If a request to start the engine is received, at step 412, the engine is started. For example, the starter motor can rotate the engine, and fuel injection can be resumed simultaneously with unlocking the transmission to increase the torque transmitted to the drive wheels to resume vehicle movement. Then, method 400 proceeds to step 414.

At step 414, the capacity of the catalytic converter for storing oxygen is determined. In accordance with one embodiment, the change in oxygen storage capacity is determined by the difference between the first capacity of the catalytic converter for storing oxygen at the time of engine start and the second capacity of the catalytic converter for storing oxygen at the time of the previous start of the engine until the cylinder is identified with a fuel injector. According to one embodiment, the capacity of the catalytic converter for storing oxygen can be determined by the oxygen concentration in the exhaust gases upstream and downstream of the catalyst determined by oxygen sensors located at the inlet and outlet of the catalyst (for example, sensors 6 and 7 in Fig. 1), the temperature of the catalytic converter, the mass flow rate of exhaust gases and / or the composition of the catalytic converter. Storage and / or conversion of fuel vapor leaking from the injector can lead to depletion of oxygen in the catalytic converter. The high capacity of the catalytic converter for storing oxygen and the low oxygen content in the catalytic converter at the time the engine is started can reduce the oxidation efficiency of the trapped fuel vapor and other exhaust components in the catalytic converter. If the oxygen content in the catalytic converter is less than a predetermined value, such oxygen content can be increased at step 416 during or after starting the engine. For example, during engine start-up after the engine is stopped, the air-fuel ratio can be adjusted (for example, the engine can be used with lean air-fuel ratio) in accordance with the change in the capacity of the catalytic converter for storing oxygen. In this way, it is possible to eliminate the effect of a fuel injector leak on the operation of the catalytic converter during engine idle stops.

In FIG. Figure 5 presents graphs of modeling the pressure in the fuel rail and the state of the fuel pump when the engine is idling. On the graph 504, the pressure in the fuel rail is plotted on the Y-axis, and the state of the fuel pump (on or off) is plotted on the Y-axis on graph 506. The x-axis represents time increasing from left to right. Vertical lines indicate key points, for example, the engine idle stop time in the interval T ₁ -T ₂ . Curves 500 and 508 show pressure changes in the fuel rail.

In the interval T ₀ -T _{1 the} fuel pump is turned on and delivers fuel to the fuel rail (graph 506), and the pressure curve in the fuel rail does not change (graph 504). When the engine is stopped at idle during the interval T ₁ -T _{2, the} fuel pump is turned off and does not supply fuel to the fuel rail. During the interval T ₁ -T _2, the graph 504 shows a slight decrease in the fuel pressure curve 500, which corresponds to a small drop in fuel pressure that is normal when the fuel pump is stopped while the engine is idling. At the same time, the decrease in the curve 508 during the interval T ₁ -T ₂ more significant (for example, due to the large drop in fuel pressure compared with the curve corresponding to the case of no fuel leakage), which indicates the presence of fuel leakage. In accordance with one embodiment, a decrease in pressure in the fuel rail when the engine is idling may indicate a leak in one or more injectors. Upon completion of the engine idle stop, that is, after the moment T ₂ , at which the fuel pump is turned on and the fuel supply to the fuel rail resumes, a corresponding increase in pressure in the fuel rail is observed, for example, as shown in graph 504.

In FIG. 6 is a graph showing the position of the intake and exhaust valves of the identified cylinder with a leak, as well as the corresponding values of the engine speed and the state of the electric motor of the starter during two operating cycles of the four-stroke engine when the engine is idling. In plot 602, the inlet valve position (curve 612) is plotted along the Y axis, and discharge valve position (curve 614) is plotted in graph 604. Graph 606 illustrates an example of changes in the state of the starter motor (curve 616), and graph 608 along the Y axis represents the engine speed (curve 618). The X axis shows the corresponding clock cycles of two consecutive engine cycles, the first cycle 610 and the second cycle 611. The first cycle 610 is the last cycle before the engine stops after the fuel injection stops. The second cycle 611 corresponds to turning on the electric motor to change the position of the motor. The duration of each of the engine cycles is indicated by vertical lines. According to one embodiment, the interval T ₀ -T ₁ corresponds to the intake stroke, followed by the compression stroke in the interval T ₁ -T ₂ , the working stroke in the interval T ₂ -T _3, and the exhaust stroke in the interval T ₃ -T ₄ . In the next cycle 611, the intake, compression, expansion, and exhaust cycles are marked, respectively, by the intervals T ₄ -T ₅ , T ₅ -T ₆ , T ₆ -T ₇ and T ₇ -T ₈ . It should be noted that the duration of different measures of the four-cycle cycle can be different, for example, each next cycle can last longer than the previous cycles, due to the slowdown of the crankshaft rotation. As the inlet valve position curve 612 shows, in the first cycle 610, the inlet valve of the identified cylinder opens at the inlet stroke T ₀ -T ₁ , wherein, as curve 614 shows, the exhaust valve is in the closed position. On the exhaust stroke, which occurs in the interval T ₃ -T ₄ , the inlet valve remains closed, and the exhaust valve is opened. As can be seen from graph 606, the starter motor in this interval does not work.

During the second cycle 611, the starter motor is turned on to turn the engine to a selected position, determined depending on the identified cylinder so as to ensure that the identified cylinder is in the state of the exhaust stroke T ₇ -T ₈ with an open exhaust valve and a closed intake valve. Then, the starter motor is turned off and the engine remains in the selected position.

In accordance with one exemplary embodiment, a change in engine position may be made depending on the readings of an electronic sensor that determines the angular position of the crankshaft at the time the engine is stopped. For example, the selected engine position may correspond to a certain range of angular positions of the crankshaft, such that the exhaust valve of the identified cylinder is at least partially open, for example, crank angles from 540 to 720 °, and the starter motor can rotate the engine until the crankshaft reaches angular position within this range of angular positions of the crankshaft. According to another embodiment, the selected engine position may correspond to the angular position of the crankshaft, such that the exhaust valve is at the highest point of rise, for example, equal to 630 °, wherein the starter motor can rotate the engine until the crankshaft reaches an angular position within the threshold deviations (e.g. equal to 10 °) from the selected position. In addition, in accordance with some of the embodiments in which the vehicle uses a variable valve timing system, the selected position may be determined depending on the state of the variable valve timing system at the time the engine is stopped. For example, at some of the engine stops, the exhaust valve of the identified cylinder can be opened at an angular position of the crankshaft of 540 to 720 °, and at other engine stops with a change in the response time of the exhaust valve, the exhaust valve of the identified cylinder can be opened at the angular position of the crankshaft between 500 and 720 ° or with another appropriate engine position. The starter motor can rotate the engine in the desired direction, determined in accordance with the position of the crankshaft, for example, in the forward or reverse direction, so as to ensure that the engine moves to the selected position with rotation to the smallest angle.

The starter motor can be activated during the decelerating rotation of the engine when it approaches a stop to reduce the energy consumption for the rotation of the engine by the starter motor, or the starter motor can be activated after the engine is stopped. According to another embodiment, an additional load can be used to influence the rotation of the engine and translate it to the selected position. For example, an air conditioning compressor may be used as an additional load on the engine. Additional load can provide an early stop of the engine compared to its rotation without additional load. According to another embodiment, a change in the position of the engine may not be necessary if the position of the engine at the time it was stopped already corresponds to the selected position. According to one embodiment, the state of the battery may affect the position of the engine, and rotation of the engine by the electric motor can only be provided if the charge of the battery exceeds a threshold charge level. Thus, setting the cylinder with the current fuel injector in a state corresponding to the exhaust stroke, in which its exhaust valve is at least partially open, when the engine is idling, allows you to eliminate the consequences of a fuel injector leak.

Although the engine shutdown procedure in the presence of a fuel injector leak has been described above as applied to the engine idle shutdown, it should be understood that the engine shutdown procedure described with reference to FIG. 4 and 6, can be performed in other cases, the engine is stopped. For example, the position of the engine can be changed so that the exhaust valve of the identified cylinder with the current fuel injector is at least partially open after stopping the engine, and during normal engine stop, upon the request of the operator. According to another embodiment, the position of the engine can be changed so that the exhaust valve of the identified cylinder with the current fuel injector is at least partially open after the engine is stopped, in the case of a hybrid vehicle switching from the engine mode to the battery mode.

The technical effect of changing the position of the engine cylinder with the current fuel injector to open its exhaust valve while the engine is idling is to allow the escape of the leaked fuel vapor into a catalytic converter, in which the fuel vapor is oxidized to reduce emission toxicity. This method also provides reduction of failures during engine restart after prolonged stops and engine starts, in particular, misfire, jerking in vehicle movement and air bubbles entering the fuel system, as well as preventing damage to the engine by leaking fuel.

A method for an engine includes: identifying an engine cylinder with a fuel injector leak; and during or after stopping the engine, setting the engine to a position selected depending on the identified cylinder, so that the exhaust valve of the identified cylinder is at least partially open. According to a first embodiment of this method, setting the engine to a selected position includes changing the position engine in the absence of combustion and movement of the vehicle without a motor drive In accordance with a second embodiment, the method may include the method according to the first embodiment, the installation of the engine in a selected position further includes rotating the engine with an electric motor to ensure that the engine stops in the selected position, so that the exhaust valve of the identified cylinder is at least partially open. According to a third embodiment, the method may include the method of the first and / or second embodiment, wherein the rotation of the engine by the electric motor to a selected position of the engine further includes rotating the engine by the electric motor when the engine is stopped. According to a fourth embodiment, the method may include a method according to one or more first to third embodiments, wherein the rotation of the engine by the electric motor to a selected engine position further includes determining a first forward rotation angle necessary to reach the selected position, determination of the second angle of rotation in the opposite direction necessary to achieve the selected position, and the rotation of the engine by the electric motor in the forward direction pressure on the first angle of rotation or rotation of the engine by an electric motor in the opposite direction to the second angle of rotation. According to a fifth embodiment, the method may include a method according to one or more of the first to fourth embodiments, and further includes rotating the motor in the opposite direction by a second angle of rotation, if the first angle of rotation is less than the second angle of rotation, and rotation engine electric motor in the forward direction to the first angle of rotation, if the first angle of rotation is greater than the second angle of rotation. According to a sixth embodiment, the method may include a method according to one or more of the first to fifth embodiments, and further includes rotating the engine with an electric motor only if the battery level exceeds a threshold charge level. According to a seventh embodiment, the method may include a method according to one or more of the first to sixth embodiments, and further includes starting the engine to idle depending on one or more of such parameters as the engine speed, position the brake pedal and the position of the accelerator pedal, and setting the engine to a selected position includes setting the engine to a selected position during or after the engine stops and idle.

In accordance with another embodiment of the invention, a method for an engine comprising a plurality of cylinders includes identifying one of a plurality of cylinders of an engine having a fuel injector leak; adjusting the amount of fuel supplied to one or more of the plurality of engine cylinders during engine operation; and setting the engine to a position selected depending on the identified cylinder, so that the exhaust valve of the identified cylinder is at least partially open, during or after engine shutdown. According to a first embodiment of this method, adjusting the amount of fuel supplied to one or more of the plurality of engine cylinders includes determining the amount of fuel flowing into the identified cylinder during an engine cycle; and reducing the amount of fuel supplied to one or more of the remaining engine cylinders in a subsequent engine cycle by an amount corresponding to the amount of fuel flowing into the identified cylinder. According to a second embodiment, the method may include the method of the first embodiment, the determination of the amount of fuel flowing into the identified cylinder during the engine cycle includes the determination of the amount of fuel flowing into the identified cylinder during the engine cycle, according to the testimony of an oxygen sensor for exhaust gases. According to a third embodiment, the method may include the method of the first and / or second embodiment, wherein determining the amount of fuel flowing into the identified cylinder during the engine cycle includes determining the amount of fuel flowing into the identified cylinder during engine operation cycle, by changing the oxygen storage capacity of the catalytic converter located downstream of the engine during engine shutdown. According to a fourth embodiment, the method may include a method according to one or more of the first to third embodiments, the change in the oxygen storage capacity being determined by the difference between the first value of the oxygen storage capacity of the catalytic converter determined at a subsequent engine start, and the second value of the oxygen storage capacity of the catalytic converter, determined during the previous start of the engine until the identification of the cylinder having fuel injector leak. According to a fifth embodiment, the method may include a method according to one or more of the first to fourth embodiments, and further includes adjusting the air-fuel ratio of the engine depending on a change in the oxygen storage capacity of the catalyst during engine start-up after stopping the engine. According to a sixth embodiment, the method may include a method according to one or more of the first to fifth embodiments, wherein the engine stop is an engine idle stop that is performed automatically depending on the amount of torque required by the operator. According to a seventh embodiment, the method may include a method according to one or more of the first to sixth embodiments, wherein setting the engine to a selected position includes adjusting the engine load while the engine is stopped. According to an eighth embodiment, the method may include a method according to one or more of the first to seventh embodiments, wherein adjusting the amount of fuel supplied to one or more of the plurality of engine cylinders includes adjusting the amount of fuel supplied to the identified cylinder .

According to another embodiment of the invention, the method for an engine comprising a plurality of cylinders includes identifying one of the plurality of cylinders having a fuel injector leak, and rotating the engine with an electric motor to achieve an engine position selected depending on the identified cylinder, during or after stopping the engine in case of leakage of the fuel injector according to the results of checking the fuel system for leaks; and maintaining the final stopping position of the engine during or after engine shutdown in the absence of detection of a fuel injector leak according to the results of checking the fuel system for a leak. According to a first embodiment of the method, the selected engine position is the engine position in which the identified cylinder is in a state of exhaust stroke. According to a second embodiment, the method may include the method of the first embodiment, the selected position being the engine position in which the exhaust valve of the identified cylinder is within a threshold deviation from the maximum lift position of the exhaust valve. According to a third embodiment, the method may include the method of the first and / or second embodiment, the preservation of the final stopping position of the engine during or after the engine is stopped in the absence of detection of a fuel injector leak, as a result of checking the fuel system for leak, includes the preservation of an arbitrary final stop position of the engine without rotating the motor by an electric motor.

It should be noted that the examples of control and evaluation algorithms included in this application can be used with various configurations of engine systems and / or vehicles. The control methods and algorithms disclosed in this application may be stored as executable instructions in long-term memory and may be executed by a control system containing controllers in combination with various sensors, actuators, and other engine components. The specific algorithms disclosed in this application may be one or any number of processing strategies such as event driven, interrupt driven, multitasking, multithreaded, etc. Thus, the illustrated various actions, operations and / or functions can be performed in the indicated sequence, in parallel, and in some cases can be omitted. Similarly, the specified processing order is not necessarily required to achieve the distinctive features and advantages of the embodiments of the invention described herein, but is for the convenience of illustration and description. One or more of the illustrated actions, operations, and / or functions may be performed repeatedly depending on the particular strategy employed. In addition, the disclosed actions, operations and / or functions may graphically depict code programmed in the long-term memory of a computer-readable storage medium in an engine control system, the disclosed actions being performed by executing instructions in a system containing various hardware components of the engine in combination with an electronic controller.

It should be understood that the configurations and programs disclosed herein are merely examples, and that specific embodiments should not be construed in a limiting sense, for various modifications thereof are possible. For example, the above technology can be applied to engines with cylinder layouts V-6, I-4, I-6, V-12, in a circuit with 4 opposed cylinders and in other types of engines. The subject of the present invention includes all new and non-obvious combinations and subcombinations of various systems and schemes, as well as other distinguishing features, functions and / or properties disclosed in the present description.

In the following claims, in particular, certain combinations and subcombinations of components that are considered new and not obvious are indicated. In such claims, reference may be made to the “one” element or the “first” element or to an equivalent term. It should be understood that such items may include one or more of these elements, without requiring or excluding two or more of these elements. Other combinations and subcombinations of the disclosed distinguishing features, functions, elements or properties may be included in the formula by changing existing paragraphs or by introducing new claims in this or a related application. Such claims, irrespective of whether they are wider, narrower, equivalent or different in terms of the scope of the idea of the original claims, are also considered to be included in the subject of the present invention.

Claims (29)

1. A method for an engine comprising a plurality of cylinders, comprising the following: identify the engine cylinder with a fuel injector leak; and during or after the engine is stopped, the engine is set to a position selected depending on the identified cylinder, so that the exhaust valve of the identified cylinder is at least partially open, moreover, when the engine is installed in the selected position, the engine is rotated by the electric motor to ensure that the engine stops in the selected position, so that the exhaust valve of the identified cylinder is at least partially open. 2. The method according to p. 1, characterized in that when the engine is installed in the selected position, the position of the engine is changed in the absence of combustion and movement without drive from the engine. 3. The method according to p. 1, characterized in that when the engine is rotated by an electric motor to a selected position of the engine, the motor is rotated by an electric motor in case of engine shutdown. 4. The method according to p. 1, characterized in that when the engine rotates the electric motor to a selected engine position, a first forward rotation angle is determined to achieve the selected engine position, a second reverse rotation angle is determined necessary to achieve the selected engine position, and rotate the motor by the electric motor in the forward direction by the first angle of rotation or rotate the motor by the electric motor in the opposite direction by the second angle of rotation. 5. The method according to p. 4, characterized in that the engine is rotated in the opposite direction by a second rotation angle, if the first rotation angle is greater than the second rotation angle, and the engine is rotated in the forward direction by the first rotation angle, if the first rotation angle is less than the second rotation angle . 6. The method according to p. 1, characterized in that when the engine is rotated by an electric motor, the motor is rotated by an electric motor in case the battery charge exceeds a threshold charge level. 7. The method according to p. 1, characterized in that it further starts to stop the engine at idle, depending on one or more of such parameters as the engine speed, the position of the brake pedal and the position of the accelerator pedal, and when the engine is installed in the selected position engine to the selected position during or after the engine has stopped idling. 8. A method for an engine comprising a plurality of cylinders, comprising the following: identifying one of a plurality of engine cylinders having a fuel injector leak; during engine operation, the amount of fuel supplied to one or more of the plurality of engine cylinders is adjusted; and during or after the engine is stopped, the engine is set to a position selected depending on the identified cylinder, so that the exhaust valve of the identified cylinder is at least partially open; moreover, the adjustment of the amount of fuel supplied to one or more of the many cylinders of the engine includes the following: determine the amount of fuel flowing into the identified cylinder during the engine cycle; and reduce the amount of fuel supplied to one or more of the remaining engine cylinders in a subsequent engine cycle by an amount corresponding to the amount of fuel flowing into the identified cylinder. 9. The method according to p. 8, characterized in that when determining the amount of fuel flowing into the identified cylinder during the engine cycle, determine the amount of fuel flowing into the identified cylinder during the engine cycle, according to the readings of the exhaust gas oxygen sensor. 10. The method according to p. 8, characterized in that when determining the amount of fuel flowing into the identified cylinder during the engine cycle, determine the amount of fuel flowing into the identified cylinder during the engine cycle by changing the oxygen storage capacity of the catalytic converter, located downstream of the engine during engine shutdown, and the change in oxygen storage capacity is determined by the difference between the first value of the oxygen storage capacity nical converter at the subsequent start of the engine, and the second value of oxygen storage capacity of the catalytic converter when the engine is started prior to the identification of a cylinder having a fuel injector to flow. 11. The method according to p. 10, characterized in that, additionally, during starting the engine produced after the engine is stopped, the air-fuel ratio of the engine is adjusted depending on the change in the oxygen storage capacity of the catalytic converter. 12. The method according to p. 8, characterized in that when adjusting the amount of fuel supplied to one or more of the plurality of engine cylinders, the amount of fuel supplied to the identified cylinder is adjusted. 13. The method according to p. 8, characterized in that the engine stop is an engine idle stop, performed automatically depending on the amount of torque required by the operator. 14. The method according to p. 8, characterized in that when the engine is installed in the selected position, the load on the engine is adjusted while the engine is stopped. 15. A method for an engine comprising a plurality of cylinders, including: if a fuel injector leak is detected, one of the plurality of cylinders having a fuel injector leak is identified by checking the fuel system for leaks, and during or after the engine is stopped, the engine is rotated by an electric motor to achieve an engine position selected depending on the identified cylinder; and if there is no leakage of the fuel injector according to the results of checking the fuel system for leaks, the final stop position of the engine is maintained during or after the engine is stopped. 16. The method according to p. 15, characterized in that the selected position of the engine is the position of the engine in which the identified cylinder is in a state of exhaust cycle. 17. The method according to p. 15, characterized in that the selected engine position is the engine position in which the exhaust valve of the identified cylinder is within a threshold deviation from the position of the maximum lift of the exhaust valve. 18. The method according to p. 15, characterized in that if there is no leakage of the fuel injector according to the results of checking the fuel system for leaks, during or after the engine is stopped, while maintaining the final stopping position of the engine, keep an arbitrary final stopping position of the engine without engine rotation electric motor.

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